The bishop on b2 secretly controls g7 and h8. Use that to mate on the back rank.
Qe8#! Normally the king escapes to g7 — but the long-diagonal bishop says no. Batteries win games.
The position, then the answer.
This lesson is one of 92 in the Grandmaster Academy — every one playable, with the pieces moving under your hand.
♔ Practise this lesson free